<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>父元素相对定位，子元素绝对定位</title>
		<style>
			#large{
				height: 500px;
				width: 600px;
				background-color: lightgray;
				position: relative;
			}
			#large .adv{
				height: 100px;
				width: 100px;
				background-color:blueviolet;
				position: absolute;
				bottom: 0;
				right: 0;
			}
		</style>
	</head>
	<body>
		<div id="large">
			<div class="adv">广告</div>
		</div>
	</body>
</html>